INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
RULE 13d-2(a)

Under the Securities Exchange Act of 1934

(Amendment No. 2)

Bloomin'
Brands, Inc.

(Name of Issuer)

Common Stock,
par value $0.01 per share

(Title of Class of Securities)

094235108

(CUSIP Number)

Eleazer Klein, Esq.

Marc Weingarten, Esq.

919 Third Avenue

New York, New York 10022

(212) 756-2000

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

February
28, 2018

(Date of Event which Requires

Filing of this Schedule)

If the filing person has previously filed a statement on Schedule
13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f)
or 13d-1(g), check the following box. [ ]

NOTE: Schedules filed in paper format shall include a signed
original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

(Continued on following pages)

(Page 1 of 6 Pages)

--------------------------

The information required on the remainder of this cover page shall
not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or
otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).

CUSIP No. 094235108

SCHEDULE 13D/A

Page 2 of 6 Pages

1

NAME OF REPORTING PERSON

JANA PARTNERS LLC

2

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ¨

(b) x

3

SEC USE ONLY

4

SOURCE OF FUNDS

AF

5

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)

¨

6

CITIZENSHIP OR PLACE OF ORGANIZATION

Delaware

NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH

7

SOLE VOTING POWER

7,929,638 Shares

8

SHARED VOTING POWER

0

9

SOLE DISPOSITIVE POWER

7,929,638 Shares

10

SHARED DISPOSITIVE POWER

0

11

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON

7,929,638 Shares

12

CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

¨

13

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) (see Item
5)

8.6%

14

TYPE OF REPORTING PERSON

IA

CUSIP No. 094235108

SCHEDULE 13D/A

Page 3 of 6 Pages

This Amendment No. 2 ("Amendment
No. 2") amends and supplements the statement on Schedule 13D filed with the Securities and Exchange Commission (the "SEC")
on November 20, 2017 (the "Original Schedule 13D") and Amendment No. 1 filed with the SEC on January 25, 2018
("Amendment No. 1", and together with Original Schedule 13D and this Amendment No. 2, the "Schedule 13D")
with respect to the shares ("Shares") of common stock, par value $0.01 per share, of Bloomin' Brands, Inc., a
Delaware corporation (the "Issuer"). Capitalized terms used herein and not otherwise defined in this Amendment
No. 2 shall have the meanings set forth in the Schedule 13D. This Amendment No. 2 amends Items 2, 3, 4, 5, 6 and 7.

As a result of the Cooperation Agreement (as defined in Item
4 of this Amendment No. 2), the Reporting Person (as defined below), Glenn K. Murphy and Neal J. Yanofsky are no longer deemed
to be a “group” for purposes of Section 13(d)(3) of the Exchange Act and Rule 13d-5(b)(1) promulgated thereunder. Therefore,
the beneficial ownership reported in this Amendment No. 2 no longer includes the beneficial ownership of Mr. Murphy or Mr. Yanofsky.

Item 2.

IDENTITY AND BACKGROUND.

Item 2 of the Schedule 13D is hereby amended and restated in its
entirety as follows:

(a) This statement is filed by JANA Partners LLC, a
Delaware limited liability company (the “Reporting Person”). The Reporting Person is a private money management
firm which holds Shares of the Issuer in various accounts under its management and control. The principal owner of the Reporting
Person is Barry Rosenstein (the “Principal”).

(b) The principal business address of the Reporting
Person and the Principal is 767 Fifth Avenue, 8th Floor, New York, NY 10153.

(c) The principal business of the Reporting Person
and the Principal is investing for accounts under their management.

(d) Neither the Reporting Person nor the Principal
has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) Neither the Reporting Person nor the Principal
has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction
and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting
or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) The Reporting Person is a limited liability company
organized in Delaware. The Principal is a United States citizen.

Item 3.

SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

Item 3 of the Schedule 13D is hereby amended and restated in its
entirety as follows:

The 7,929,638 Shares reported herein by the Reporting
Person were acquired at an aggregate purchase price of approximately $136.5 million. Such Shares were acquired with investment
funds in accounts managed by the Reporting Person and margin borrowings described in the following sentence. Such Shares are held
by the investment funds managed by the Reporting Person in commingled margin,

CUSIP No. 094235108

SCHEDULE 13D/A

Page 4 of 6 Pages

accounts which may extend
margin credit to the Reporting Person from time to time, subject to applicable federal margin regulations, stock exchange rules
and credit policies. In such instances, the positions held in the margin accounts are pledged as collateral security for the repayment
of debit balances in the account. The margin accounts bear interest at a rate based upon the broker's call rate from time to time
in effect. Because other securities are held in the margin accounts, it is not possible to determine the amounts, if any, of margin
used to purchase the Shares reported herein.

Item 4.

PURPOSE OF TRANSACTION.

Item 4 of the Schedule 13D is hereby amended and supplemented by
the addition of the following:

On February 28, 2018, the Reporting Person entered
into a cooperation agreement with the Issuer (the "Cooperation Agreement") and issued a joint press release
with the Issuer announcing the Cooperation Agreement and certain of its material terms (the "Press
Release"). The full text of the Cooperation Agreement and Press Release are included as Exhibit E and Exhibit
F, respectively, to this Amendment No. 2 by reference to Exhibits 10.1 and 99.1 of the Issuer's Current Report on Form
8-K filed with the SEC on February 28, 2018 (the "Form 8-K") and is incorporated by reference herein.

Item 5.

INTEREST IN SECURITIES OF THE ISSUER.

Items 5(a), (b), (c) and (d) of the Schedule
13D are hereby amended and restated in their entirety as follows:

(a) The aggregate percentage of
Shares reported to be beneficially owned by the Reporting Persons is based upon 91,913,000 Shares outstanding as of December
31, 2017, as reported in Exhibit 99.1 of the Issuer's Current Report on Form 8-K filed with the Securities and Exchange
Commission on February 22, 2018.

As of the close of business on the
date hereof, the Reporting Person may be deemed to beneficially own 7,929,638 Shares, representing approximately 8.6% of the Shares
outstanding.

By virtue of the Cooperation
Agreement the Reporting Person, Mr. Murphy and Mr. Yanofsky are no longer deemed to be a “group” for purposes of Section
13(d)(3) of the Exchange Act and Rule 13d-5(b)(1) promulgated thereunder. As a result, this Amendment No. 2 only reports the beneficial
ownership of the Reporting Person.

(b) The Reporting Person has sole
voting and dispositive power over 7,929,638 Shares, which power is exercised by the Principal.

(c) There were no transactions in the Shares effected
by the Reporting Person since Amendment No. 1.

(d) No person (other than the Reporting Person) is known
to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Shares.

CUSIP No. 094235108

SCHEDULE 13D/A

Page 5 of 6 Pages

Item 6.

CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER.

Item 6 of the Schedule 13D is hereby amended
and supplemented as follows:

On February 28, 2018, the Issuer and the
Reporting Person entered into the Cooperation Agreement. A copy of such agreement is attached as Exhibit E to this
Amendment No. 2 and is incorporated by reference herein.

Item 7.

MATERIAL TO BE FILED AS EXHIBITS.

Item 7 of the Schedule 13D is hereby amended
and supplemented as follows:

Exhibit E:

Cooperation Agreement, dated February 28, 2018 (incorporated by reference to Exhibit 10.1 to the Form 8-K).

Exhibit F:

Press Release, issued on February 28, 2018 (incorporated by reference to Exhibit 99.1 to the Form 8-K).

CUSIP No. 094235108

SCHEDULE 13D/A

Page 6 of 6 Pages

SIGNATURES

After reasonable inquiry and to the best
of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.